<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <link rel="stylesheet" href="base.css" />
    <style>
      .box {
        width: 50px;
        cursor: pointer;
        text-align: center;
        background-color: #ccc;
        position: relative;
      }
      .content {
        height: 60px;
        width: 0;
        word-wrap: break-word;
        overflow: hidden;
        position: absolute;
        top: 0;
        left: 50px;
      }

      .box:hover > .content {
        display: block;
        width: 50px;
        border: 1px solid #000;
        /* animation: grow 3s ease-out 0s 1; */
      }

      @keyframes grow {
        from {
          width: 0px;
        }
        to {
          width: 50px;
        }
      }
    </style>
  </head>
  <body>
    <div class="box">
      <a href="javascript:void(0);">文字</a>
      <div class="content">123123182389</div>
    </div>
  </body>
</html>
